COOLING FAN AND SYSTEM PERFORMANCE AND EFFICIENCY IMPROVEMENTS

PDF Version Also Available for Download.

Description

Upcoming emissions regulations (Tiers 3, 4a and 4b) are imposing significantly higher heat loads on the cooling system than lesser regulated machines. This work was a suite of tasks aimed at reducing the parasitic losses of the cooling system, or improving the design process through six distinct tasks: 1. Develop an axial fan that will provide more airflow, with less input power and less noise. The initial plan was to use Genetic Algorithms to do an automated fan design, incorporating forward sweep for low noise. First and second generation concepts could not meet either performance or sound goals. An experienced ... continued below

Creation Information

Dupree, Ronald July 31, 2005.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 24 times , with 4 in the last month . More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

Upcoming emissions regulations (Tiers 3, 4a and 4b) are imposing significantly higher heat loads on the cooling system than lesser regulated machines. This work was a suite of tasks aimed at reducing the parasitic losses of the cooling system, or improving the design process through six distinct tasks: 1. Develop an axial fan that will provide more airflow, with less input power and less noise. The initial plan was to use Genetic Algorithms to do an automated fan design, incorporating forward sweep for low noise. First and second generation concepts could not meet either performance or sound goals. An experienced turbomachinery designer, using a specialized CFD analysis program has taken over the design and has been able to demonstrate a 5% flow improvement (vs 10% goal) and 10% efficiency improvement (vs 10% goal) using blade twist only. 2. Fan shroud developments, using an 'aeroshroud' concept developed at Michigan State University. Performance testing at Michigan State University showed the design is capable of meeting the goal of a 10% increase in flow, but over a very narrow operating range of fan performance. The goal of 10% increase in fan efficiency was not met. Fan noise was reduced from 0 to 2dB, vs. a goal of 5dB at constant airflow. The narrow range of fan operating conditions affected by the aeroshroud makes this concept unattractive for further development at this time 3. Improved axial fan system modeling is needed to accommodate the numbers of cooling systems to be redesigned to meet lower emissions requirements. A CFD fan system modeling guide has been completed and transferred to design engineers. Current, uncontrolled modeling practices produce flow estimates in some cases within 5% of measured values, and in some cases within 25% of measured values. The techniques in the modeling guide reduced variability to the goal of + 5% for the case under study. 4. Demonstrate the performance and design versatility of a high performance fan. A 'swept blade mixed flow' fan was rapid prototyped from cast aluminum for a performance demonstration on a small construction machine. The fan was mounted directly in place of the conventional fan (relatively close to the engine). The goal was to provide equal airflow at constant fan speed, with 75% of the input power and 5 dB quieter than the conventional fan. The result was a significant loss in flow with the prototype due to its sensitivity to downstream blockage. This sensitivity to downstream blockage affects flow, efficiency, and noise all negatively, and further development was terminated. 5. Develop a high efficiency variable speed fan drive to replace existing slipping clutch style fan drives. The goal for this task was to provide a continuously variable speed fan drive with an efficiency of 95%+ at max speed, and losses no greater than at max speed as the fan speed would vary throughout its entire speed range. The process developed to quantify the fuel savings potential of a variable speed fan drive has produced a simple tool to predict the fuel savings of a variable speed drive, and has sparked significant interest in the use of variable speed fan drive for Tier 3 emissions compliant machines. The proposed dual ratio slipping clutch variable speed fan drive can provide a more efficient system than a conventional single ratio slipping clutch fan drive, but could not meet the established performance goals of this task, so this task was halted in a gate review prior to the start of detailed design. 6. Develop a cooling system air filtration device to allow the use of automotive style high performance heat exchangers currently in off road machines. The goal of this task was to provide a radiator air filtration system that could allow high fin density, louvered radiators to operate in a find dust application with the same resistance to fouling as a current production off-road radiator design. Initial sensitivity testing demonstrated that fan speed has a significant impact on the fouling of radiator cores due to fine dusts, so machines equipped with continuously variable speed fan drives would be expected to have more radiator debris fouling problems than a machine with a constant speed fan. Filtration concepts looked at a wide range of filtration technologies, but the combination of pressure drop constraints and the small size of the debris to be filtered made this a futile exercise. The most successful technologies evaluated all incorporate some way to increase the Reynolds number inside the heat exchanger air flow path. A form of an 'air knife' concept has emerged as the most promising technology to pursue.

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Report No.: None
  • Grant Number: FC26-02AL68081
  • DOI: 10.2172/1028966 | External Link
  • Office of Scientific & Technical Information Report Number: 1028966
  • Archival Resource Key: ark:/67531/metadc833991

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • July 31, 2005

Added to The UNT Digital Library

  • May 19, 2016, 3:16 p.m.

Description Last Updated

  • Dec. 5, 2016, 1:16 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 4
Total Uses: 24

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Dupree, Ronald. COOLING FAN AND SYSTEM PERFORMANCE AND EFFICIENCY IMPROVEMENTS, report, July 31, 2005; United States. (digital.library.unt.edu/ark:/67531/metadc833991/: accessed September 23, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.